Electrical relay construction



Sept. 19, 1933. E. L. FONSECA ELECTRICAL RELAY CONSTRUCTION Filed Feb.17, 1930 Pat en ted Sept. 19,

PATENT OFFICE 1,927,026 ELECTRICAL RELAY CONSTRUCTION Edward L. Fonseca,Newark, N. J., assignor to I The Wilcolator Company, Newark, N. J., acorporation of Delaware Application February 17, 1930. Serial No.429,084

' 4 Claims. ((1200-1 17 This invention relates to electrical relays andhas particular reference to the arrangement and construction of certainparts of direct current relays. I F

The principal objects of this invention are to provide novel means foreliminating the damaging effects of the arc which forms between theseparating contacts of a relay, and also to provide a relay constructedin a novel way whereby ef-= ficient operation, simplicity of manufactureassembly, and low cost are obtained.

These and other objects are obtained in a ierred embodiment of theinvention which consists in mounting upon the usual insulating baseplate a pair of spaced members of magnetic terial which serve assupports for line resistance units or the like, and as poles for amagnetic arc blow-out, the field coil of which is mounted be tween thesemembers, preferably below the contacts of the relay. Insulating these manetic pole members from the arc and defining the magn tic air-gap aresheets of insulating material. he i ing these insulating sheets againstthe faces the pole members and spacing them apart is e of insulatingmaterial which is placed across magnetic air-gap in the path of the arcand which serves as an arc-splitter to prevent the from flashing backbetween the contacts or conducting parts.

accompanying drawing, in which Figure 1 illustrates in elevation onement of the invention;

Fig. 2 is a front view thereof; and

Fig. 3 is an enlarged fragmentary cross-section thereof as seen alongthe line 3--3 of Fig. i.

In the drawing, numeral 10 designates the base of the relay, this basebeing formed of insulating material such as porcelain, composition, orany or the other usual insulating-materials. Mounted "2 a bracket llsecured. to the base 10 is the magt coil 12 of the relay, the core 13 ofwhich projects upwardly for cooperation with the armature 14, which isin the form of a plate pivoted at one end upon pointed screws 15 securedin bracket ill.

The moving contact arm 16 of the relay is secured to so as to be movableby the armature 14 by means of a pin 17 mounted upon armature ltl,

this pin 17 carrying the washers 18 between which is mounted a coilspring 19. This coil spring 19 normally keeps the armature 14 and thecontact arm 16 in engagement, although armature 14 and contact arm 16are relatively movable. The rear end-of contact arm 16 is piloted inposition by means of a screw 20 projecting through an oversize hole inthe armature, this screw serving as a binding post for one side of thecircuit controlled.

by the relay. The front end of contact arm 16 carries the movable relaycontact 21 adapted to cooperate with the fixed relay contact 22. Whenrelay magnet coil 12 is de-ener moving relay contact 21 is heldseparated i om fixed relay contact 22 by the coil spring 23 se=- curedat one end to the rear end of armature l i and at the other cruel to apin 24. mounted upon the rear surface of bracket ll. The space be tweenrelay contacts 21 and 22 is less than the space between armature 14- andthe core 13 of relay coil 12 when relay coil 12 is deenergized.

' This is done in order that a good, positive contact is made betweenrelay contacts 21 and 22 when relay coil 12 is energy the a nature i lof the relay accordingly being 1 into engagement with core 13 throughgreater distance of .1, than the movement of contact 21 to "ed contact22. will accordingly be e t when the relay is energized, armature tedslightly from contact arm 16 against in of spring 19, which has theadditional. so effect of producing a sli ht wiping betwee'". contacts 2iand 22, whereby their engaging s faces lrept in good contactingcondition all times.

Set in a transverse groove in the top sur 'c of base plate is andsecured thereto are pair U-shaped brackets 25 which are forme of steelor some other good magnetic ina l.

brackets 25 serve as the poles for magnetic arc blcw ouathe fieldwinding of wh ch is mounted in yoke 2'1 secured by sore". s or he like28 to the brackets 25. The yoke 2'? caries the fixed relay contact 22and the binding post 29, to which one terminal or the circuit controlled by the relay is connected.

Insulating the relay contacts 21 and 22 the pole brackets 25 anddefining the magnetic air-gap are a pair of insulating sheets 30 of micaor other good insulating material, these sheets being placed between theopposite sides or" yoke 2'3 and the corresponding surfaces of pole brackets 25, as shown particularly in Figs. 2 and. 3h

Spacing and securing in place these mica sheets 30 is a rod 31 ofrefractory and insulating material, such as Rockbestos or other similarmaterial, this rod 31 having tenon ends set in corresponding aperturesthrough the mica sheets 30 and the pole brackets 25, as shownin Fig. 3.The rod 31 is placed in front of and slightly above the relay contacts21 and 22 and serves as a mechanical arc-breaking agent or arc-splitterfor the are formed between contacts 21 and 22 when they separate, thisare being drawn forward by the magnetic field created between polebrackets 25 by the field winding 26. The arc, although drawn forward andblown out by the magnetic fleld flux between pole brackets 25, tends toflash back and maintain itself between relay contact 22 and some portionof the contact arm 16 or other metal part after the contacts 21 and 22have separated. The flame of the arc tends to flash upwardly and back,but the rod 31 is so positioned that the flame cannot flash in thisdirection, but only in a forward direction, where it can do no harm andwhere it is eventually blown out by the magnetic circuit.

Mounted in brackets 25 are auxiliary electrical units 32, which, in theparticular embodiment illustrated, are resistance coils insulated inporcelain or the like. These resistance units are of the commercialtype, consisting of hollow porcelain tubes which are held in place inbrackets 25 by means of rods 33 passing through them and tapped into thelower arms of brackets 25 so that the units 32 may be readily emplacedand removed. These resistance units 32 may be used for any purpose, suchas reducing the current through the relay magnet winding 12 or the arcblowout winding 26 when the units are connected in series therewith, orfor any other purpose. Although resistance units 32 have beenillustrated and described, other electrical units might be used in asimilar way, the pole brackets 25 serving as a convenient and efiectivesupport therefor.

The novel relay of this invention operates similarly to relays now inuse insofar as electrical action thereof is concerned, the energizationof relay coil 12 causing the connection of armature 14 and core 13, withthe consequent earlier and perfect, slightly wiping engagement of relaycontacts 21 and 22. The relay contacts 21 and 22 remain closed as longas relay coil 12 is energized, but when the latter is de-energized,spring 23 pulls armature 14 away from core 13 about the pivot screws 15and separates relay contacts 21 and 22. The usual are produced upon theseparation of relay contacts 21 and 22 is drawn forward and blown out bythe magnetic field flux formed across the air-gap between poles 25 bythe magnetic winding 26. Frequently, however, before the arc is blownout, it flashes up and back to maintain itself between fixed relaycontact 22 and some metallic part 0! the moving contact the relaycontacts 21 and 22, so that the path of 21, such as the contact arm 16.In order to prevent the are from flashing up and back, it is broken orsplit mechanically by the refractory rod 31 placed slightly in front andslightly above the arc is lengthened to such an extent that before thearc can travel the added distance around rod 31 and back to the contactarm 16 or other metallic part, it is blown out by the magnetic heldbetween poles 25.

It will be seen that the new relay 0! this invention provides manyadvantages over relays heretofore provided, principal among which is theeffective are elimination without expensive or complicated parts, but,on the contrary, by few' and inexpensive parts which form importantelements in the construction of the relay as a whole. For example, thearc spliter 31 serves as a spacer and support for the mica sheets 30,and the poles 25 serve as brackets for the electrical units 32, and forma generally compact unit which is inexpensive to manufacture andassemble, and which is not likely to get out of order.

I claim:

1. In an electrical device having separable electrical contacts andmagnetic field poles mounted on opposite sides of the contacts forblowing out the are formed between them, the combination of an insulatoron the face of each of said poles, and a member extending between saidpoles for securing said insulators to the faces of said pole andpositioned adjacent the contacts in the direction of movement of the areformed between them for breaking the arc.

2. In an electrical device having separable electrical contacts and apair of magnetic field poles supported adjacent the contacts, thecombination of lateral extensions on said poles, and independentelectrical units supported by said extensions.

3. In an electrical device having an insulating base, the combination ofU-shaped brackets of magnetic material mounted upon said base andindependent insulated electrical units mounted between the arms of eachof said brackets.

4. In an electrical device having separable contacts and a base, thecombination of members mounted on the base at either side of thecontacts, an insulating sheet on the inner surface of each member, and arod extending between the sheets 5 forsecuring them to the correspondingmembers and positioned in the path of the arc formed be tween themembers for breaking the arc.

EDWARD L. FONSECA.

